GW200208_222617 as an eccentric black-hole binary merger: properties and astrophysical implications

A few of us met at the GWsnowballs workshop earlier this year, and during a scientific discussion, I ended up asking: “What’s the current gravitational-wave event with signs of eccentricity that are the least ambiguous?” I argued against the usual suspect, GW190521, because that signal is too short—and short makes it ambiguous. Then we looked at two analyses that searched for eccentricity in the current gravitational-wave catalog. They flagged several events, but only one appeared in both. The “telephone number” of that event is GW200208_222617, and that discussion eventually led to this paper.

I. Romero-Shaw, J. Stegmann, H. Tagawa, D. Gerosa, J. Samsing, N. Gupte, S. R. Green.
arXiv:2506.17105 [astro-ph.HE].